Inside A DEC Hard Drive

April 19, 2021 by Al Williams 40 Comments

A lot of technology from the not-so-distant past doesn’t resemble modern versions very much. For a case in point, look at the DEC RS08 disk drive meant to pair with a circa 1970 PDP-8. Paired with an RF08 controller, this was state of the art, holding 262K 12-bit words with a blistering access speed of almost 63K/second unless you were plugged into 50Hz AC when it was closer to 50K/second. [Uniservo] had the disk unit, but not the controller. Someone else had a controller, but no disk drive. So [Uniservo] is shipping the disk to its new owner in a move worthy of a Reeses’ Peanutbutter Cup. The problem? The disk is super fragile and shipping is risky, so he decided to remove the platter for separate packing. Good thing for us, because we get a peek inside.

The nickel-cobalt platter looks like a thick LP record with heads underneath. As you might guess from the data transfer specification, the motor was just a common AC motor that rotated the platter against the head.

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Teardown: Linkimals Musical Moose

April 13, 2021 by Tom Nardi 23 Comments

Like so many consumer products these days, baby toys seem to get progressively more complex with each passing year. Despite the fact that the average toddler will more often than not be completely engrossed by a simple cardboard box, toy companies are apparently hell-bent on producing battery powered contraptions that need to be licensed with the FCC.

As a perfect example, we have Fisher-Price’s Linkimals. These friendly creatures can operate independently by singing songs and flashing their integrated RGB LEDs in response to button presses, but get a few of them in the room together, and their 2.4 GHz radios kick in to create an impromptu mesh network of fun.

They’ll soon be back, and in greater numbers.

Once connected to each other, the digital critters synchronize their LEDs and sing in unison. Will your two year old pay attention long enough to notice? I know mine certainly wouldn’t. But it does make for a compelling commercial, and when you’re selling kid’s toys, that’s really the most important thing.

On the suggestion of one of our beloved readers, I picked up a second-hand Linkimals Musical Moose to take a closer look at how this cuddly pal operates. Though in hindsight, I didn’t really need to; a quick browse on Amazon shows that despite their high-tech internals, these little fellows are surprisingly cheap. In fact, I’m somewhat embarrassed to admit that given its current retail price of just under $10 USD, I actually paid more for my used moose.

But you didn’t come here to read about my fiscal irresponsibility, you want to see an anthropomorphic woodland creature get dissected. So let’s pull this smug Moose apart and see what’s inside.

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Taking A Peek Inside The Newest Echo Show 10

April 9, 2021 by Tom Nardi 26 Comments

When Amazon released the original Echo, it was a pretty simple affair. Cylinder, some LEDs on top, done. Then they came out with the Echo Dot, which was basically the same thing, but shorter. It seemed like there was a pretty clear theme for awhile, but then at some point Amazon decided it would be a good idea to start producing Echo devices in every form factor imaginable, from wall plugs to literal sunglasses, and things got a lot more complicated. As a perfect example, take a look at this teardown of the third generation Echo Show 10 by [txyzinfo].

Granted the base still looks a bit like the Echos of old, but the family resemblance stops there. As you can probably gather from the name, the Show features a high resolution 10.1 inch LCD panel, greatly improving the number and type of advertisements Amazon is able to force on the user. In true Black Mirror fashion, there’s even a brushless motor in the base that allows the machine to rotate the display towards the user no matter how hard they try to escape.

A salvageable part if there ever was one.

The teardown is presented with no commentary; in both the video below and on the Hackaday.IO page, all you’ll find are clear and well-lit images of the device’s internals. But for those who are just interested in what the inside of one of these $250 USD gadgets looks like, that’s all you really need.

At this point, it doesn’t seem like [txyzinfo] is trying to reverse engineer the Show or figure out how it all works, and looking at the complexity of that main board, we’re not surprised. Still, it’s a marvel to look at all the hardware they packed into such a relatively small device.

If you’re looking for a more technical examination at the newer Echo devices, [Brian Dorey] did some impressive poking around on the third generation Dot in 2019 and [electronupdate] went as far as decapping a few of the chips inside the Flex. On the software side of things, check out the recent efforts to craft an open source firmware for the original Echo.

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Teardown: Go Warmer USB Rechargeable Hand Heater

March 9, 2021 by Tom Nardi 31 Comments

Under normal circumstances, if an electronic gadget in your pocket suddenly became hot to the touch, it would be cause for alarm. But not so with the Go Warmer. This lozenge shaped device is not only a USB power bank that can keep your mobile devices topped up, but is also doubles as a miniature heater that the manufacturer claims can bring its surface temperature up to 48 °C (120 °F) for several hours. You can hold in in your hand, put it in your pocket, maybe even sit on it if you’re particularly daring. The possibilities are endless, at least until the 4,000 mAh battery runs down.

For $14.99 USD, the Go Warmer certainly isn’t much of a deal when compared to other battery packs. Even if it does come with a swanky velveteen carrying pouch. But is it a good deal for one that can heat itself up without exploding? Let’s crack this metallic egg and find out.

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Inside An Oscillator With [Ken Shirriff]

February 21, 2021 by Al Williams 13 Comments

We are always glad to see [Ken Shirriff] tear into something new and this month he’s looking inside a quartz oscillator module. Offhand, you’d think there’s not much to these. A slab of quartz and some sort of inverter, right? But as [Ken] mentions, “There’s more happening in the module than I expected…”

If you’ve ever wanted to decap devices, big hybrid modules like these are a good way to get started since you don’t need exotic chemicals to get at the insides. [Ken] managed to break the fragile crystal wafer on the way in. Inside was also a small CMOS IC die. Time to get out the microscope.

If you follow [Ken’s] blog, you know he’s no stranger to analyzing IC dice. The oscillator IC is a pretty standard Colpitts oscillator but it also provides a programmable divider and output drive.

The circuit uses some unusually configured capacitors. [Ken] takes the time to point out CMOS logic structures throughout. If you haven’t seen one of [Ken’s] deep dives before, before, it’s a great introduction.

You can learn more about crystal oscillator theory. We used some test equipment to characterize a crystal a few years ago.

Teardown: Bug Zapper Bulb

February 9, 2021 by Tom Nardi 17 Comments

Up here in the Northern Hemisphere, mosquitoes and other flying pests are the last thing on anyone’s mind right now. The only bug that’s hindering gatherings at the moment goes by the name of COVID-19, but even if we weren’t social distancing, insects simply aren’t a concern at this time of year. So it’s little surprise that these months are often the best time to find a great deal on gadgets designed to deter or outright obliterate airborne insects.

Case in point, I was able to pick up this “Bug Zapper LED Bulb” at the big-box hardware store for just a few bucks. This one is sold by PIC Corporation, though some press release surfing shows the company merely took over distribution of the device in 2017. Before then it was known as the Zapplight, and was the sort of thing you might see advertised on TV if you were still awake at 3 AM. It appears there are several exceptionally similar products on the market as well, which are likely to be the same internally.

In all fairness, it’s a pretty clever idea. Traditional zappers are fairly large, and need to be hoisted up somewhere next to an electrical outlet. But if you could shrink one down to the size of a light bulb, you could easily dot them around the porch using the existing sockets and wiring. Extra points if you can also figure out a way to make it work as a real bulb when the bugs aren’t out. Obviously the resulting chimera won’t excel at either task, but there’s certainly something to be said for the convenience of it.

Let’s take a look inside one of these electrifying illuminators and see how they’ve managed to squeeze two very different devices into one socket-friendly package.

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Mystery Box Gives Up Its Patented Secrets

January 31, 2021 by Al Williams 21 Comments

[CuriousMarc] likes to go to surplus stores even though there are fewer of them around. On a recent trip, he found a box that had some parts he thought would work for a temperature controller project. It was marked Dial-A-Level and proudly proclaimed that it had a patent pending. The box was from the 1970s and [Marc] was wondering what the device was meant to do.

The device was a bit of a puzzle since it had three oddly-marked probe inputs. A search through the patent database revealed the device was a “capacitance probe for detecting moisture with very long cables.” The idea was to create a capacitor at the end of the cable and use the liquid as a dielectric. The sensor creates a 10 kHz sine wave it uses to excite the probe and an op amp measures the relative capacitive reactance of the probe versus a reference capacitor. The rest of the circuit is a comparator that reacts when the level is at a threshold.

We love seeing the old hand-drawn boards from that era. Component designations are in copper and there’s no solder mask visible. There was a clever application of a silicon controlled rectifiers and a relay to create a type of flip flop, that [Marc] explains.

Interestingly, the company that made the device, Expo Instruments, is still around and [Marc] contacted them. The actual patent holder replied and was amazed that [Marc] had possession of this antique. You can only wonder if anything you build today will wind up on whatever passes for YouTube three or four decades from now.

Capacitive sensing is quite versatile. Of course, there are many other ways to sense liquid level, too.

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